This invention relates to a transparent electrically conductive plate exhibiting ultraviolet shielding performance useful for a variety of electronic devices.
The electronic devices employing liquid crystal or electrochromic material are deteriorated by irradiation with ultraviolet rays. If an ultraviolet shielding layer is provided below the transparent electrically conductive layer for prohibiting such deterioration, the abrasion resistance, for example of the glass of the electronic device is not lowered. However, high vacuum and high temperature are required for fabrication of the transparent electrically conductive layer, such as ITO. An ultraviolet absorbing layer containing an organic ultraviolet absorber alone cannot withstand these conditions, such that sufficient performance cannot be achieved due to volatilization of the organic ultraviolet absorber.
For overcoming these inconveniences, attempts have been made for providing an ultraviolet absorbing layer outside of the device and providing a glass layer on the ultraviolet absorbing layer as disclosed in, for example Japanese Laid-open Patent Publication No. 1-276120 (1989). However, this complicates the structure and increases the number of process steps. Although attempts have also been made in providing a dichroic layer as shown in Japanese Laid-open Patent Publication No. 63-236016 (1988), this structure leads to elevated production costs. Although attempts have also been made in providing an ultraviolet absorbing layer containing metal oxides as shown in Japanese Laid-open Patent Publication No. 62-148339 (1987), the near-ultraviolet area cannot be shielded satisfactorily.